[rtmpdump] Can't get rtmpdump to work with CSPAN

[Steve Gorwood]

I am having trouble downloading CSPAN video using rtmpdump (version 2.3) on 
kubuntu 11.4.  For example, the url:

http://www.c-spanvideo.org/program/MobileTechn

When I try to use the parameters:

rtmpdump -r rtmp://video.c-spanarchives.org:1935/fastplay/../ -y 
mp4:full/2011/05/19/20110519200000002_hd.mp4 -A 84 -B 3602 -W  http://www.c-
spanarchives.org/flash/cspanPlayer.swf -o MobileTechn_0.mp4

The dump begins correctly at 2.3%.  It proceeds for a while, then drops back 
and redownloads a portion of the earlier stream.  It will do this repeatedly 
as the dump proceeds so that the final file will contain many repeated segments.

I used rtmpsrv to get (hopefully) better parameters.  Rtmpsrv gave me the 
following command line: 

rtmpdump -r "rtmp://video.c-spanarchives.org:1935/fastplay" -a "fastplay" -f 
"LNX 10,3,181,14" -W "http://www.c-
spanvideo.org/videoLibrary/assets/swf/CSPANPlayer.swf?rand=1249707438" -p 
"http://www.c-spanvideo.org/program/MobileTechn" -y 
"mp4:full/2011/05/19/20110519200000002_hd.mp4" -o 20110519200000002_hd.flv

This gave me the same behavior.

If I add the -V parameter, I observe that I get the following information at 
the point of the problem:

7741.721 kB / 158.22 sec (4.3%)
DEBUG: HandleCtrl, received ctrl. type: 31, len: 6
DEBUG: HandleCtrl, Stream BufferEmpty 1
DEBUG: HandleCtrl, received ctrl. type: 1, len: 6
DEBUG: HandleCtrl, Stream EOF 1
DEBUG: RTMP_ClientPacket, received: invoke 208 bytes
DEBUG: (object begin)
DEBUG: Property: NULL
DEBUG: (object begin)
DEBUG: Property: <Name:              level, STRING:     status>
DEBUG: Property: <Name:               code, STRING:     
NetStream.Pause.Notify>
DEBUG: Property: <Name:        description, STRING:     Pausing 
full/2011/05/19/20110519200000002_hd.mp4.>
DEBUG: Property: <Name:            details, STRING:     
full/2011/05/19/20110519200000002_hd.mp4>
DEBUG: Property: <Name:           clientid, NUMBER:     504348861.00>
DEBUG: (object end)
DEBUG: (object end)

I have found that if I use the --live parameter, the behavior improves, 
although I get occasional video corruption.

Is there anything that I can do to fix this problem?